Bar guide for machine tools



NOV. 21, 1933. K TESSKY 1,935,999

BAR GUIDE FOR MACHINE TOOLS Filed Aug. 13, 1930 C 5 Fly. 7. Figa. H99.

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in the tube.

Patented Nov. 21, 1933 i Unirse sTATEs PATENT OFFICE Application August 13, 1930, Serial No. 474,948, and in Germany August 24, 1929 7 Claims.

In the guiding means of the type aforesaid av tube is provided in which a coil spring enclosed which acts as a sound deadening lining of the guide tube, whereby the noise caused by the rapidly rotating bar-shaped blanks is greatly reduced, while at the same time wear or and injury to the blanks is eectually avoided.

In the bar guide according to the present invention the coil spring forming the lining of the guide tube is formed in such manner that each winding is in contact with the tube as well as with the bar to be fed in such manner that the portions of the spring extending between the points of contact are free to exert a certain spring action.

In the drawing aixed to the specification and forming part thereof several forms of ablank guiding device embodying my invention are illustrated diagrammatically by way of example.

In the drawing Fig. l is a cross section and Fig. 2 an axial section of the rst modification,

Figs. 3 and Il are similar Views of a second modication,

Fig. 5 being another longitudinal section of this latter modification drawn to a smaller scale,

Fig. 6 is a cross section of a third modiiication,

Fig. '2 being an end view oi a mandrel used for winding the coilv spring, and

Fig. 8 showing part or". a spring wound around this mandrel.

Fig. 9 is an axial section drawn to a smaller scale of the same modification.

Figs. lo-ii are similar views of a fourth modification. I

Referring to the drawing and first to Figs. 1 and 2, d is the blank or workpiece, b is the guide tube and c is the coil spring forming the lining "I e the windings of the spring are equal in di eter, however the spring is so formed that longitudinal extends in a helical line as indicated in dash lines. In consequence of this orrnation each winding is in conwinding of the imaginary helical axis of the coil may vary within wide limits.

In the modification illustrated in Figs. 3-5 four windings of the spring marked l, 2, 3 and 4 are distributed over each winding of the axis, the 60 points of contact with .the outer tube and the inner barl being marked I, II, III and IV in Fig. 3.

It may however also prove advantageous to have each spring winding contact with the workpiece in more than one point. In that casethe free resilient portions of the winding will bcconie comparatively short, so that a wire of comparatively small diameter can be chosen in order to still obtain a certain spring action in the transversal direction. In consequence thereof the 70 weight of the coil spring will be very low and the guide as a whole will be lighter and more handy, which is important in view of the fact that the guide tube must frequently be rocked by hand whenever a new workpiece is inserted.

A modication answering these conditions is illustrated in Figs. 6-9. I-Iere the spring is wound around a mandrel, such as shown in Fig. '7, having substantially the cross section of a rectangle with rounded edges. If the spring is wound around this mandrel, as shown in Fig. 8, after removal from the mandrel it will assume the form shown in Figs. 6 and 9.

As shown in Fig. 6 the top winding contacts with the bar a in three points I, II, IIIv and similarly in three points with the outer tube b. The strap-shaped portions of the spring between two points of contact serve for resiliently supporting and for deadening the noise of the bar.

In the modification illustrated in Figs. 10-13 the spring has been wound around a mandrel as shown in Fig. 11, which also has the cross section of a rectangle with rounded edges, however of a much iiatter shape. The spring thus obtained is particularly useful as a resilient guide in the case where the diameter of the bar-shaped workpiece is small as compared with the diameter of the guide tube. If bars of greater diameter shall be guided in the same tube the spring shown in Fig. 10 may be removed and one of the springs shown in the other figures may be inserted.

Obviously springs of different forms can be devised and used in connection with this workpiece guide without departing from the spirit of my invention.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described for obvious modifications will occur to a person skilled in the art.

In the claims aixed to this specification no selection of any particular modification of the invention is intended to the exclusion of other modifications thereof and the right to subsequently make claim to any modification not covered by these claims is expressly reserved.

I claim:-

1. Bar guide for machine tools comprising a guide tube and a coil spring in said tube said spring being so shaped that each spring winding is in contact both with said tube and with the bar guided in said tube.

2. Bar guide for machine tools comprising a guide tube and a coil spring in said tube arranged to guide the bar, each spring winding being in contact both with said tube and with the bar, a point of contact between the spring and the tube being spaced from an adjoining point of Contact between the spring and the bar less than one spring winding.

3. Bar guide for machine tools comprising a guide tube and a coil spring having eccentric windings in and contacting with said tube in a helical line.

4. Bar guide for machine tools comprising a guide tube and a non-cylindrical coil spring in said tube, the consecutive windings of said spring contacting with said tube only. in spaced intervals, the points of contact being arranged on a helical line of higher pitch than the spring windings.

5. Bar guide for machine tools comprising a guide tube and a non-cylindrical coil spring in said tube arranged to guide the bar, the consecutive windings of said spring contacting with the inner surface of said tube and the outer surface of the bar only in spaced intervals, the points of contact being arranged on helical lines of higher pitch than the spring windings.

6. Bar guide for machine tools comprising a guide tube and a coil spring in said tube, the consecutive windings of said spring having smaller diameters than the inside of said tube, and the centres of the windings of said spring being disposed on a helical line. v

'7. Bar guide for machine tools comprising a guide tube and a coil spring in said tube, the consecutive windings of said spring having smaller diameters than the inside of said tube, and the centres of the windings of said spring being disposed on a helical line of such a diameter that the windings of said spring contact with the bar iiipoints arranged on a helical line of higher pitch than the spring windings.

KARL TESSKY. 

